{"id":"CVE-2026-68090","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-68090","generatedAt":"2026-10-28T03:26:17.945Z","title":"In the Linux kernel, the following vulnerability has been resolved: debugobjects: Plug race against a concurrent OOM disable syzbot reported a puzzling splat: WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20 stub_timer() is installed as timer…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndebugobjects: Plug race against a concurrent OOM disable\n\nsyzbot reported a puzzling splat:\n\n   WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20\n\nstub_timer() is installed as timer callback function in\nhrtimer_fixup_assert_init(), which is invoked when\ndebug_object_assert_init() can't find a shadow object. In that case debug\nobjects emits a warning about it before invoking the fixup.\n\nThough the provided console log lacks this warning and instead has the\nfollowing a few seconds before the splat:\n\n     ODEBUG: Out of memory. ODEBUG disabled\n\nSo the object was looked up in debug_object_assert_init() and the lookup\nfailed due a concurrent out of memory situation which disabled debug\nobjects and freed the shadow objects:\n\ndebug_object_assert_init()\n        if (!debug_objects_enabled)\n        \treturn;                         obj = alloc();\n                \t\t\t\tif (!obj) {\n\t\t\t\t\t\t\t// Out of memory\n                                                \tdebug_objects_enabled = false;\n                                                        free_objects();\n        obj = lookup_or_alloc();\n\n        // The lookup failed because the other side\n        // removed the objects, so this returns\n        // an error code as the object in question\n        // is not statically initialized\n\n\tif (!IS_ERR_OR_NULL(obj))\n        \treturn;\n        if (!obj) {\n        \tdebug_oom();\n                return;\n        }\n\n        print(...)\n           if (!debug_objects_enabled)\n                return;\n\n        fixup(...)\n\nThe debug object splat is skipped because debug_objects_enabled is false,\nbut the fixup callback is invoked unconditionally, which makes the timer\ndisfunctional.\n\nThis is only a problem in debug_object_assert_init() and\ndebug_object_activate() as both have to handle statically initialized\nobjects and therefore must handle the error pointer return case\ngracefully. All other places only handle the found/not found case and the\nNULL pointer return is a signal for OOM. Otherwise they get a valid shadow\nobject.\n\nPlug the hole by checking whether debug objects are still enabled before\ninvoking the print and fixup function in those two places.","published":"2026-08-10T12:17:22.000Z","lastModified":"2026-08-17T05:18:08.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00177,"percentile":0.07153,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/1f4f02b336c3be125c8fcf87df73db2e0e028b8b","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/203a965bf2ab43130778d8214fb0c3c8c2d19cdf","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/23da32e88627e63e0864f59f4c63a2dc0ab851a3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2d5e320b7ab9b25229ac4331541964a58b5e1d29","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b81dde13cc163450dcb402dcc915ef13ba241e01","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c00164c9e7fa6145886ad666806cb5347895de5c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d663fbf28b2eebe665bb9cf828d7d528e5a8707e","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e2e255d07723c330dded8e576ce28a8d23a692ce","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68090","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}